1. High Speed Sync supported for 1D X and 5D3 (but also worked on the reviewers 5D2 all the way to 1/8000sec)2. Tested to a Range of 100m (340') worked flawlessly in an open field (Canon's Spec claims 30m/98')3. There will be a non radio 600EX for countries that haven't adopted the 2.4gHz for unlicensed devices.

But, regardless of what the manual states, he was able to use HSS on both his 5D2 and 60D, up to 1/8000sec.

Actually, I just had another look at my manual and there is a fine print that says "Canon advises you to upgrade your gear to the newest Canon stuff as soon as possible. Canon will make sure that your new gear doesn't work with your old gear (see no radio addon for legacy 580ex flashes), but even if it does, Canon won't tell you and you shouldn't bother."

But, regardless of what the manual states, he was able to use HSS on both his 5D2 and 60D, up to 1/8000sec.

Actually, I just had another look at my manual and there is a fine print that says "Canon advises you to upgrade your gear to the newest Canon stuff as soon as possible. Canon will make sure that your new gear doesn't work with your old gear (see no radio addon for legacy 580ex flashes), but even if it does, Canon won't tell you and you shouldn't bother."

"Actually, I just had another look at my manual and there is a fine print that says "Canon advises you to upgrade your gear to the newest Canon stuff as soon as possible. Canon will make sure that your new gear doesn't work with your old gear (see no radio addon for legacy 580ex flashes), but even if it does, Canon won't tell you and you shouldn't bother.""

This is exactly what I am afraid of...

Surely the pre-production version of 600EX-RT worked with 5d2 re: HSS. I hope Canon doesn't intentionally cripplethe production version of the 600EX-RT to force us to upgrade to 5d3 or 1dx.